mod 5 IQ1

Question 1

what is the formula for gibbs free energy

Answer 1

ΔG=ΔH−TΔS

change in enthalpy kJ minus change in entropy in kJ/K

Question 2

what happens when ΔG=0

Answer 2

the process is at equilibrium

Question 3

what happens when ΔG < 0

Answer 3

the process is spontaneous

Question 4

what happens when ΔG > 0

Answer 4

process is non-spontaneous

Question 5

how do you convert degrees to kelvin

Answer 5

add 273.15

Question 6

what does a reaction need for it to be considered as an equilibrium system

Answer 6

it needs to be spontaneous and reversible and in a closed system

Question 7

what does a positive entropy mean

Answer 7

disorder

Question 8

what does a negative entropy mean

Answer 8

order

Question 9

how do you calculate entropy

Answer 9

ΔS = (entropy of products) - (entropy of reactants)

Question 10

how do you calculate entropy by looking at the equation

Answer 10

if there is an increase in moles from reactants to products –> entropy increases
if there is a decrease in moles from reactants to products –> entropy decreases

note: if there are multiple states the production of gases increase entropy more

Question 11

what is an example of an equilibrium system

Answer 11

iron nitrate + potassium thiocyanate
iron nitrate is yellow and potassium thiocyanate is colourless. This produces potassium thiocyanate which is blood red.
IONIC EQUATION:
Fe3+ + SCN- ⇋ FeSCN2+